updated changelog

Author: rashtao

ChangeLog.md

@@ -7,6 +7,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/) a
 ## [Unreleased]
 
 - fixed active failover behavior for the asynchronous driver 
+- deprecated `ArangoIterable` methods in favour of Java 8 Stream equivalents
 
 ## [6.10.0] - 2021-03-27